Endoscopic vascular decompression for the treatment of trigeminal neuralgia: clinical outcomes and technical note

Standard operating procedure and surgical technique innovation in fully endoscopic microvascular decompression for trigeminal neuralgia: technical note on 189 patients

BACKGROUND

Microvascular decompression (MVD) is a well-established and effective treatment for primary trigeminal neuralgia (TN). Endoscopy has been implemented to provide a comprehensive view of neurovascular conflict and minimizes the damages of brain retraction during MVD.

OBJECTIVES

To preliminarily evaluate the surgical safety and efficacy of fully endoscopic microvascular decompression (EMVD) for primary TN with surgeon performing two-hand manipulation and assistant holding endoscope.

METHODS

Retrospective clinical analysis of 189 patients with primary TN underwent EMVD between June 2019 and August 2022 was performed. By analyzing the intraoperative situation, the outcomes of postoperative symptoms and the main complications, we evaluated the reliability and effectivity of the operative technique in the treatment of primary TN.

RESULTS

We summarized the standard operating procedure of EMVD for primary TN with surgeon performing two-hand manipulation and assistant holding endoscope. In addition, acicular bipolar electrocoagulation technique was developed to handle venous compression. During the follow-up period, good pain relief was achieved in 178 patients (94.2%) and recurrence of pain was observed in 4 patients (2.1%). Postoperative temporary complications included trigeminal dysesthesias (7 patients, 4.8%), cerebrospinal fluid leak (2 patients, 1.1%), hearing difficulty (3 patient, 1.6%), facial paresis (2 patients, 1.1%) and vertigo (5 patients, 2.7%). There were no cases of intracranial hemorrhage, cerebellar swelling and death.

CONCLUSION

This EMVD technique is reliable and effective, and can be used as a routine surgical procedure for primary TN.

Fully Endoscopic Microvascular Decompression for Trigeminal Neuralgia Caused by Vertebrobasilar Artery: A Case Series Review: 2-Dimensional Operative Video

BACKGROUND AND OBJECTIVE

Microvascular decompression (MVD) is the most definitive and preferred surgical treatment for trigeminal neuralgia (TN). Treatment of TN caused by the vertebrobasilar artery (VBA) has been reported to be challenging and less satisfactory in complications and recurrence. Endoscopy has been implemented to provide a comprehensive view of neurovascular conflicts and minimize brain tissue stretch injury while exploring the trigeminal nerve. However, there are few retrospective studies on the treatment of TN caused by VBA by fully endoscopic microvascular decompression (E-MVD). This article aimed to illustrate the safety and efficacy of E-MVD for TN caused by the VBA.

METHODS

Clinical data for 26 patients with TN caused by the VBA who underwent E-MVD from 2019 to 2022 were retrospectively analyzed. The characteristics of vertebrobasilar-associated TN were summarized. The safety and efficacy of E-MVD for vertebrobasilar-associated TN were estimated based on the analysis of intraoperative manipulation, postoperative symptom relief, and complications.

RESULTS

Intraoperatively, the vertebrobasilar artery was regarded as a direct offending vessel in all 26 patients with TN, the vertebral artery in 18 (69.23%) and the basilar artery in 10 (38.46%). In addition to the vertebrobasilar artery, other vessels involved included the superior cerebellar artery in 12 patients, anterior inferior cerebellar artery in 9, posterior inferior cerebellar artery in 1, and veins in 4. All patients underwent E-MVD, and TN was entirely resolved in 26 (100%) patients immediately postoperatively. During the follow-up period of 12-45 months, no recurrence or serious complications were found. There were no serious postoperative complications, such as cerebellar swelling, intracranial hemorrhage, or death.

CONCLUSION

E-MVD for vertebrobasilar-associated TN is effective and safe.

Endoscopic microvascular decompression versus microscopic microvascular decompression for trigeminal neuralgia: A systematic review and meta-analysis

BACKGROUND

To compare the efficacy and safety of full endoscopic or endoscope-assisted microvascular decompression (E-MVD) and microscopic microvascular decompression (M-MVD) for primary trigeminal neuralgia (TN).

METHODS

We systematically searched the online database, including PubMed, Embase and Cochrane Library. The search terms used included, but were not limited to, "Trigeminal Neuralgia", "Microvascular Decompression Surgery" and "Endoscope". Postoperative facial pain relief and postoperative complications were considered for meta-analysis. All the outcomes were calculated as odds ratios (ORs) with 95% confidence intervals using R language.

RESULTS

A total of three studies involving 442 (E-MVD [218] versus M-MVD [224]) patients were included for analysis in our study. Postoperative facial pain relief (very much improved or much improved) was no difference between the two groups (OR, 0.95;95% CI, 0.57-1.58; I2 = 0%; p = 0.83). In addition, the occurrence of some postoperative complications was not statistically different between the two groups, including CSFleak (OR, 1.35;95% CI, 0.16-11.13; I2 = 0%; p = 0.94), facial paralysis (OR, 0.26;95% CI, 0.03-2.54; I2 = 0%; p = 0.67), hearing loss (OR, 0.87;95% CI, 0.30-2.55; I2 = 32%; p = 0.22), facial numbness (OR, 1.03;95% CI, 0.56-1.87; I2 = 62%; p = 0.10).

CONCLUSIONS

Both endoscopic microvascular decompression and microscopic microvascular decompression for trigeminal neuralgia appear to provide patients with equivalent facial pain relief outcomes. Complication rates were also similar between the groups.

Fully Endoscopic Microvascular Decompression for Trigeminal Neuralgia: Technical Note Describing a Single-Center Experience

BACKGROUND

Microscopic microvascular decompression (MVD) of the trigeminal nerve is the gold standard surgical treatment for medically refractory classical trigeminal neuralgia. Endoscopy has significantly advanced surgery and provides enhanced visualization of the cerebellopontine angle and its critical neurovascular structures. We present our initial experience of fully endoscopic microvascular decompression (e-MVD).

METHODS

This retrospective case series investigated e-MVD performed from September 2016 to February 2020 at a single institution. Clinical data including presenting symptoms, medications, operative findings, postoperative complications, and outcomes were recorded. The 5-point Barrow Neurological Institute (BNI) pain intensity score was used to quantify patients' pain relief.

RESULTS

During the study period, 25 patients with trigeminal neuralgia (10 males, 15 females; mean [SD] age = 63 [10.4] years) underwent e-MVD. All patients had a preoperative BNI score of V. The left side was affected in 15 patients. Complications occurred in 2 patients: both experienced hearing loss, and one experienced transient facial weakness 7 days after surgery. The facial weakness had resolved by the last follow-up. All patients were completely pain-free (BNI score I) immediately postoperatively. On latest follow-up, 22 patients have remained pain-free, and 3 patients have recurrent pain that is being controlled with medication (BNI score III).

CONCLUSIONS

Our study demonstrated that e-MVD is a safe, possibly effective method of performing MVD with the added benefit of improved visualization of the operative field for the operating surgeon and the surgical team. Larger prospective studies are required to evaluate whether performing e-MVD confers any additional benefits in long-term clinical outcome of patients with trigeminal neuralgia.

Endoscopic Vascular Decompression for the Treatment of Trigeminal Neuralgia: Clinical Outcomes and Technical Note

Purpose

Microvascular decompression (MVD) surgery is considered as an effective method with which to treat trigeminal neuralgia (TN). However, sometimes MVD surgery fails due to incomplete decompression of the responsible vessels caused by a poor visual field. In this study, we evaluated the benefits of endoscopic visualization and the value of full endoscopic vascular decompression (EVD) by describing the surgical results of 20 patients with TN after EVD.

Patients and Methods

This was a retrospective study in a single institution of 20 patients with TN who received EVD between April 2018 and October 2019. All patients underwent EVD via the suboccipital retrosigmoid approach without microscopy at any stage. Abnormal muscle response (AMR) and brainstem auditory evoked potentials (BAEPs) were routinely monitored throughout the procedure. Follow-up was conducted by outpatient and telephone interviews. The degree of facial pain was graded using the Barrow Neurological Institute (BNI) pain intensity score; a BNI of 1 was considered as the best result while a BNI of 2 or 3 was considered as a satisfactory result. Follow-up time ranged from 8 to 24 months, with a mean of 18±4.36 months.

Results

All 20 patients with severe preoperative pain (BNI of 5) achieved immediate relief or complete control of pain after surgery (BNI of 1 to 2). Vascular conflicts were observed during surgery in all of the patients. None of the patients experienced hearing loss, facial paralysis, intracranial infection, cerebrospinal fluid leakage, cerebral hemorrhage, or death, following the operation.

Conclusion

When carried out by surgeons with endoscopic experience, EVD can provide a clear surgical field of view and reduce the risk of surgical injury. Our findings indicate that EVD is a safe and effective surgical method for the treatment of TN.

Treatment Outcomes in Trigeminal Neuralgia-A Systematic Review of Domains, Dimensions and Measures

BACKGROUND

Trigeminal neuralgia (TN) is a painful disorder characterized by sudden electric shock-like pain. It is a rare condition for which multiple treatments are available, including medical and surgical. The best treatment option is yet to be defined, and this is related to the lack of definition in the treatment outcomes and outcome measures. The aim of this systematic review was to summarize all the outcomes and outcomes measures that have been published to date and highlight variability in their use.

METHODS

We have conducted a literature search using a wide range of databases (1946-2019 for medical and 2008-2019 for surgical treatment), for all intervention studies in TN. Four hundred and sixty-seven studies were selected for data extraction on TN classification, data collection method, intervention, and treatment outcomes mapped to the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT guidelines).

RESULTS

Most studies collected data on pain (n = 459) and side effects (n = 386) domains; however, very few collected data on the impact of treatment on physical (n = 46) and emotional functioning (n = 17) and on patient satisfaction (n = 35). There was high variability on outcome measures used for pain relief (n = 10), pain intensity (n = 9), and frequency of pain episodes (n = 3).

CONCLUSIONS

A clear definition of what are the important outcomes for patients with TN is essential. The choice of standardized outcome measures allowing for consistent reporting in TN treatment will allow for comparison of studies and facilitate treatment choice for patients and clinicians thus, improving health outcomes and reducing health care cost.

Complication Rates During Endoscopic Microvascular Decompression Surgery Are Low With or Without Petrosal Vein Sacrifice

OBJECTIVE

Endoscopic-microvascular decompression (E-MVD) is a well-described treatment for trigeminal neuralgia (TGN), but there has been debate on the safety of intraoperative sacrifice of the petrosal vein (PV) due to concern for subsequent venous insufficiency. Our objective was to investigate the risk of PV sacrifice during E-MVD in TGN and subsequent postoperative complications and pain outcomes.

METHODS

5 five-year review yielded 201 patients who underwent MVD for TGN. PV sacrifice, vascular compressive anatomy, and postoperative complications attributable to venous insufficiency were analyzed. Preoperative and postoperative pain outcomes were analyzed.

RESULTS

PV was sacrificed in 118 of 201 (59%) of patients, with 43 of 201 (21%) patients undergoing partial sacrifice versus 75 of 201 (37%) with complete sacrifice. No cases of venous infarction, cerebellar swelling, or fatal complications were noted in either cohort. Non-neurologic complications occurred in 1.69% (2 of 118) of patients with PV sacrifice and 0% (0 of 83) of patients with PV preservation. Neurologic deficits (facial palsy, conductive hearing loss, gait instability, memory deficit) occurred in equal proportions in PV preservation and sacrifice groups (2.41% vs. 1.69%) Overall, 87.3% (145 of 166) patients reported their pain as "very much improved" or "much improved" at 1 month, and no difference between groups was identified.

CONCLUSIONS

This study did not find higher complication rates in patients undergoing petrosal vein sacrifice during E-MVD for trigeminal neuralgia. In this series where petrosal vein was sacrificed only 59% of the time, it appears to be a safe technique, but larger studies will be needed to determine true incidence of complications after PV sacrifice.

How I do it: 3D exoscopic endoscope-assisted microvascular decompression

BACKGROUND

Microvascular decompression (MVD) is an effective treatment for drug-resistant trigeminal neuralgia and hemifacial spasm. However, failure of symptomatic improvement can arise from difficulties in identifying and/or decompressing the offending vessel. Microscopic and endoscopic techniques have been used to improve visualisation and safety of the procedure but there are limitations to each technique.

METHOD

A 3D exoscopic endoscope-assisted MVD technique is described, including advice on potential pitfalls.

CONCLUSION

Compared with the standard microscope-assisted techniques, the 3D exoscopic endoscope-assisted MVD offers an improved visualisation without compromising the field of view within and outside the surgical field.

Veins of the Cerebellopontine Angle and Specific Complications of Sacrifice, with Special Emphasis on Microvascular Decompression Surgery. A Review

Good knowledge of the anatomy of veins is of crucial importance for the functional surgery of cranial nerve (CN) disorders, especially microvascular decompression for trigeminal neuralgia (TN), hemifacial spasm (HFS), and vagoglossopharyngeal neuralgia (VGPN). Although controversial, veins may be involved in neurovascular conflicts and may constitute dangerous obstacles to access to the CNs. With the aim of estimating the implications of veins in those diseases and evaluating the linked surgical difficulties, we carried out a review of the literature from 2000 to the end of February 2018. For this review, articles found on PubMed that gave enough precision about veins were retained (39 articles on TN, 38 on HFS, 8 on VGPN, and 26 on complications related to venous sacrifices). Before this review, we described a simplified anatomic classification of veins, amenable to easing the surgical approach to CNs. Access to the trigeminal nerve, via the infratentorial-supracerebellar route, is almost always affected by the superficial superior petrosal venous system, whereas access to the facial and cochleovestibular complex as well as to the lower CNs, through the infrafloccular trajectory, is almost always exempt of important venous obstacles. Respective incidences of venous compression at the origin of hyperactive CN syndromes are given. The percentages of a venous conflict alone were calculated at 10.8% for TN, 0.1% for HFS, and 2.9% for VGPN. We review the complications considered in relation with venous sacrifices. Precautions to minimize these complications are given.

Endoscopic versus microscopic microvascular decompression for trigeminal neuralgia: equivalent pain outcomes with possibly decreased postoperative headache after endoscopic surgery

OBJECTIVE

Endoscopic surgery has revolutionized surgery of the ventral skull base but has not yet been widely adopted for use in the cerebellopontine angle. Given the relatively normal anatomy of the cerebellopontine angle in patients with trigeminal neuralgia (TN), the authors hypothesized that a fully endoscopic microvascular decompression (E-MVD) might provide pain outcomes equivalent to those of microscopic MVD (M-MVD) but with fewer complications.

METHODS

The authors conducted a single-institution, single-surgeon retrospective study with patients treated in the period of 2006–2013. Before surgery, all patients completed a questionnaire that included a validated multidimensional pain-outcome tool, the Penn Facial Pain Scale (PFPS, formerly known as Brief Pain Inventory–Facial), an 11-point scale that measures pain intensity, interference with general activities of daily living (ADLs), and facial-specific ADLs. Using a standardized script, independent research assistants conducted follow-up telephone interviews.

RESULTS

In total, 167 patients were available for follow-ups (66.5% female; 93 patients underwent M-MVD and 74 underwent E-MVD). Preoperative characteristics (i.e., TN classification, PFPS components, and medication use) were similar for the 2 surgical groups except for 2 variables. Patients in the M-MVD group had slightly higher incidence of V3 pain, and the 2 groups differed in the date of surgery and hence in the length of follow-up (2.4 years for the M-MVD group and 1.3 years for the E-MVD group, p < 0.05). There was a trend toward not finding neurovascular conflict at the time of surgery more frequently in the M-MVD than in the E-MVD group (11% vs 7%, p = 0.052). Internal neurolysis was more often performed in the E-MVD group (26% vs 7%, p = 0.001). The 2 groups did not significantly differ in the length of the MVD procedure (approximately 2 hours). Self-reported headaches at 1 month postoperatively were present in 21% of the patients in the M-MVD group versus 7% in the E-MVD group (p = 0.01). Pain outcomes at the most recent followup were equivalent, with patients reporting a 5- to 6-point (70%–80%) improvement in pain intensity, a 5-point (85%) improvement in pain interference with ADLs, and a 6-point (85%) improvement in interference with facial-specific ADLs. Actuarial freedom from pain recurrence was equivalent in the 2 groups, with 80% pain control at 3 years.

CONCLUSIONS

Both the fully endoscopic MVD and the conventional M-MVD appear to provide patients with equivalent pain outcomes. Complication rates were also similar between the groups, with the exception of the rate of headaches, which was significantly lower in the E-MVD group 1 month postoperatively.

Safety of Superior Petrosal Vein Sacrifice During Microvascular Decompression of the Trigeminal Nerve

BACKGROUND

Microvascular decompression (MVD) is a safe and effective treatment for trigeminal neuralgia. Cerebellar venous infarction is a complication associated with surgical sacrifice of the superior petrosal vein (SPV). The SPV intervenes between the trigeminal nerve and the surgeon. Optimal exposure of the cisternal trigeminal nerve, particularly at the brainstem, can be achieved by sacrificing the SPV. We analyzed a cohort of 224 patients to determine the frequency of cerebellar venous infarction.

METHODS

Retrospective analysis of records and neuroradiology for patients undergoing trigeminal MVD at the Manchester Skull Base Unit between August 1st 2008 and July 31st 2015.

RESULTS

A total of 184 of 224 (82%) patients had coagulation and division of the main stem of the SPV. There were no cases of venous infarction. There was one case of mild, transient, cerebellar symptoms and signs, with no radiologic evidence of venous infarction. This patient had SPV sacrifice at surgery but also had postoperative thrombosis of the transverse sinus. Venous sinus thrombosis affected 5 of 184 (2.7%) patients. A total of 208 of 224 (93%) patients had a good outcome with improvement or resolution of their trigeminal neuralgia at 3 months.

CONCLUSIONS

The overall rate of venous complications in this study was 2.7%; however, we had no cases of venous infarction in 184 patients who had sacrifice of the SPV. The incidence of venous infarction associated with SPV obliteration during MVD surgery is therefore <0.5%. SPV sacrifice may be used where necessary to optimize visualization of the root entry zone and maximize the chance of effective decompression of the trigeminal nerve.

Efficacy of stereotactic gamma knife surgery and microvascular decompression in the treatment of primary trigeminal neuralgia: a retrospective study of 220 cases from a single center

OBJECTIVES

A retrospective study was undertaken to compare the efficacy of stereotactic gamma knife surgery (GKS) and microvascular decompression (MVD) in the treatment of primary trigeminal neuralgia (TN) at a single center. The study included the evaluation of clinical outcomes of pain relief and pain recurrence and complications associated with GKS and MVD.

METHODS

The study included 202 patients with primary TN and was conducted between January 2013 and December 2014; about 115 patients were treated with GKS and 87 patients were treated with MVD. TN pain was evaluated using the Barrow Neurological Institute and the visual analog scale scoring systems. Preoperative magnetic resonance tomographic angiography was performed for all patients. Microscope-assisted MVD used the suboccipital retrosigmoid sinus approach. GKS targeted the trigeminal nerve root entry zone with a margin radiation dose of 59.5 Gy, and brainstem dose <12 Gy. Posttreatment follow-up was for 2 years.

RESULTS

Postoperative Barrow Neurological Institute scores for patients treated with GKS and MVD were significantly improved compared with preoperative scores (P<0.01). Reduction in postoperative pain following MVD (95.4% patients) was significantly greater than that following GKS (88.7% patients) (P<0.01). Postoperative visual analog scale scores of the MVD group were significantly reduced compared with those of patients treated with GKS at the same postoperative time points (P<0.01). Patients treated with GKS had a significantly increased rate of loss of corneal reflex compared with patients treated with MVD (P=0.002).

CONCLUSION

Both GKS and MVD are safe and effective first-line and adjunctive treatment options for patients with TN. The clinical outcomes of pain relief and reduction of pain recurrence were better with MVD. For GKS, this study showed that the optimal radiation therapeutic dose range was 70-90 Gy, but brainstem radiation protection is recommended.

Microsurgical treatment of trigeminal neuralgia in patients older than 70 years: An efficacy and safety study

INTRODUCTION

The increasing incidence of trigeminal neuralgia (TN) with age together with population ageing call for reexamination of surgical treatment options for refractory TN in elderly patients.

METHODS

Retrospective review of a consecutive series of patients older than 70 who underwent microvascular decompression (MVD) for refractory TN between 1997 and 2015. Outcomes based on the Barrow Neurological Institute pain intensity score (BNI score) and surgical complications were compared to those of patients younger than 70 undergoing MVD in the same period.

RESULTS

Forty patients older than 70 (mean = 74.8 years) underwent interventions. At a mean follow-up time of 34 months, 73% of the patients presented complete absence of pain without medication (BNI I) and 85% had good pain control with or without medication (BNI I-III). A comparison of these patients with the 85 patients younger than 70 treated surgically during the same period did not find a significant association between age and achievement of pain control (BNI I-II). However, there was a significant association between age older than 70 and complete pain relief (BNI I; P=.03). The mean hospital stay in patients over 70 was also significantly longer (P=.04), although the postsurgical complication rate was similar to that in younger patients.

CONCLUSIONS

Elderly patients with refractory TN may benefit from treatment with MVD and the probability of success and surgical risk are comparable to those in younger patients.

Fully Endoscopic Retrosigmoid Vestibular Nerve Section for Refractory Meniere Disease

OBJECTIVE

This study aims to report our results and technical details of fully endoscopic retrosigmoid vestibular nerve section.

DESIGN

A prospective observational study was conducted.

SETTING

A single academic, tertiary institution involving neurosurgery and neurotology.

PARTICIPANTS

Previously diagnosed patients with Meniere disease, refractory to medical therapy, who underwent fully endoscopic vestibular nerve section.

MAIN OUTCOME MEASURES

Postoperative improvement in vertiginous symptoms as well as hearing preservation, based on the American Association of Otolaryngology-Head and Neck Surgeons score and the Gardener and Robertson-Modified Hearing Classification. Facial nerve preservation based on the House-Brackman (HB) score.

RESULTS

Symptoms improved or resolved in 38 of 41 (92.2%) patients with only 1 of 41 (2.4%) reporting worsening symptoms. All 41 patients (100%) had a postoperative HB score of 1/6, demonstrating full facial nerve preservation. Hearing was stable or improved in 34 of 41 (82.9%) patients. Three complications took place for a rate of 7.3%, one cerebrospinal fluid leak, and two wound infections.

CONCLUSION

The fully endoscopic approach to vestibular nerve sections is a safe and effective technique for the treatment of medically refractory Meniere disease. This technique also utilizes smaller incisions, minimal cranial openings, and no cerebellar retraction with improved visualization of the cerebellopontine angle neurovascular structures.

Pre-operative image-based segmentation of the cranial nerves and blood vessels in microvascular decompression: Can we prevent unnecessary explorations?

OBJECTIVES

This study was conducted to validate the accuracy of image-based pre-operative segmentation using the gold standard endoscopic and microscopic findings for localization and pre-operative diagnosis of the offensive vessel.

PATIENTS AND METHODS

Fourteen TN and 6 HS cases were randomly selected. All patients had 3T MRI, which included thin-sectioned 3D space T2, 3D Time of Flight and MPRAGE Sequences. Imaging sequences were loaded in BrainLab iPlanNet and fused. Individual segmentation of the affected cranial nerves and the compressing vascular structure was performed by a neurosurgeon, and the results were compared with the microscopic and endoscopic findings by two blinded neurosurgeons. For each case, at least three neurovascular landmarks were targeted. Each segmented neurovascular element was validated by manual placement of the navigation probe over each target, and errors of localization were measured in mm.

RESULTS

All patients underwent retro-sigmoid craniotomy and MVD using both microscope and endoscope. Based on image segmentation, the compressing vessel was identified in all cases except one, which was also negative intraoperatively. Perfect correspondence was found between image-based segmentation and endoscopic and microscopic images and videos (Dice coefficient of 1). Measurement accuracy was 0.45 ± 0.21 mm (mean ± SD).

CONCLUSION

Image-based segmentation is a promising method for pre-operative identification and localization of offending blood vessels causing HFS and TN. Using this method may prevent some unnecessary explorations on especially atypical cases with no vascular contacts. However, negative pre-operative image segmentation may not preclude one from exploration in classic cases of TN or HFS. A multicenter study with larger number of cases is recommended.

Fully endoscopic microvascular decompression for trigeminal neuralgia: technique review and early outcomes

OBJECT

Fully endoscopicmicrovascular decompression (E-MVD) of the trigeminal nerve was initially described more than 1 decade ago, but has not yet gained wide acceptance. The authors present the experience of their first 47 consecutive E-MVDs for trigeminal neuralgia (TN).

METHODS

All surgeries were performed by a single surgeon (J.Y.K.L.) at the Pennsylvania Hospital at the University of Pennsylvania. Patients prospectively completed pain scales before and after surgery by using the Brief Pain Inventory-Facial outcomes tool. All patients were called on the telephone, and the same outcome tool was administered without reference to their preoperative pain status.

RESULTS

Forty-seven patients (17 men) were identified and enrolled. Forty (85%) had Burchiel Type 1 TN. Vascular compression was observed at surgery in 42 patients (89%). No surgery was aborted or converted to microscope. One patient suffered permanent hearing loss, for a permanent neurological morbidity rate of 2%. Overall improvement in pain outcomes was excellent, with a median maximum pain intensity preoperatively of 10 and postoperatively of 0 (p< 0.0001). The mean interference with global function scores were 6.2 preoperatively and reduced to 1.0 at last follow-up (p < 0.0001). The mean interference with facial function was 7.3 preoperatively and reduced to 1.2 at last follow-up (p < 0.0001). The mean follow-up period after surgery was 15 ± 8 months.

CONCLUSIONS

In experienced hands, E-MVD offers superb visualization and illumination and is both safe and effective, at least in the short term. Further longer-term study is needed to compare E-MVD to traditional microscopic MVD.

Trigeminal neuralgia due to neurovascular conflicts from venous origin: an anatomical-surgical study (consecutive series of 124 operated cases)

BACKGROUND

Veins as the source of trigeminal neuralgias (TN) lead to controversies. Only a few studies have specifically dealt with venous implication in neurovascular conflicts (NVC). The aim of this study was the anatomical-surgical description of the compressive veins found during micro-vascular decompression (MVD).

METHODS

Patients retained were those in whom a vein was considered compressive, alone, or in association with an artery. The study defined the type of vein involved, its situation along, the location around the root, and management. For this study, denomination of veins in relation with the root was revisited.

RESULTS

Of the 326 consecutive patients who underwent MVD from 2005 to 2013, 124 (38.0 %) had a venous conflict, alone in 29 (8.9 %), or in association with an artery in 95 (29.1 %). The compressive veins belonged to one of the two venous systems described: the superficial or the deep superior petrosal venous system (sSPVS or dSPVS). A vein from sSPVS was found compressive in 81 cases (59.6 %), for the major part it was the pontine affluent of the superior petrosal vein (48 cases). The conflict was situated at TREZ in 28.4 %, mid-cisternal portion in 50.6 %, and porus in 8.6 %. The dSPVS was found compressive in 55 cases (40.4 %), almost always a transverse vein at porus (51 cases). Decompression was coagulation-division of the conflicting vein in 36.8 % and simple cleavage in the other.

CONCLUSIONS

The study shows the frequent implication of veins in NVC as the source of TN. NVC are not only at TREZ but also at mid-cisternal portion and porus of Meckel cave.

Endoscopic Resection of Vestibular Schwannomas

Objective To report our results and the technical details of fully endoscopic resection of vestibular schwannomas. Design Prospective observational study. Setting A single academic institution involving neurosurgery and neurotology. Participants Twelve consecutive patients who underwent fully endoscopic resection of a vestibular schwannoma. Main Outcome Measures Hearing preservation, based on the American Association of Otolaryngology-Head and Neck Surgeons (AAO-HNS) score as well as the Gardener and Robertson Modified Hearing Classification (GR). Facial nerve preservation based on the House-Brackmann (HB) score. Results All patients successfully underwent gross total resection. Facial nerve preservation rate was 92% with 11 of 12 patients retaining an HB score of 1/6 postoperatively. Hearing preservation rate was 67% with 8 of 12 patients maintaining a stable AAO-HNS grade and GR score at follow-up. Mean tumor size was 1.5 cm (range: 1-2 cm). No patients experienced postoperative cerebrospinal fluid leak, infection, or cranial nerve palsy for a complication rate of 0%. Mean operative time was 261.6 minutes with an estimated blood loss of 56.3 mL and average length of hospital stay of 3.6 days. Conclusion A purely endoscopic approach is a safe and effective option for hearing preservation surgery for vestibular schwannomas in appropriately selected patients.